Problem: What's the first wrong statement in the proof below that $ \triangle BCE \cong \triangle BDE$ $ \; ?$ $ \overline{BC} $ is parallel to $ \overline{DF} $. This diagram is not drawn to scale. $A$ $B$ $C$ $D$ $E$ $F$ Givens $ \overline{BD} \cong \overline{CF}$ $, \ $ $ \angle DBE \cong \angle CFE$ $, \ $ $ \angle BED \cong \angle CEF$ $, \ $ $ \angle BED \cong \angle BAC$ $, \ $ $ \overline{DE} \cong \overline{AC}$ $, \ $ and $\ $ $ \angle BDE \cong \angle ACB$ Proof $ \triangle FCE \cong \triangle BDE$ because AAS $ \overline{CE} \cong \overline{DE}$ because corresponding parts of congruent triangles are congruent $ \angle DBE \cong \angle BEC$ because corresponding parts of congruent triangles are congruent $ \triangle BDE \cong \triangle BCA$ because ASA $ \overline{BE} \cong \overline{EF}$ because corresponding parts of congruent triangles are congruent $ \triangle BCE \cong \triangle BDE$ because SSS
Try going through the proof yourself: write down the givens, and then see if they justify the next step for the reason given. Then do the same thing for the next step, and the next, until you run into something that you can't justify, or you finish the proof. $ \angle BEC \cong \angle DBE$ is the first wrong statement.